Sawmill carriage dog



Aug. 2e,- 1930.

Y w. c'. BIDWELL ET AL 1,174,311 'sAwM'ILL CARRIAGE Doe `Filed May 14J 1928 2 Sheets-Sheet l Aug 25, 1930 w. c. BlDwELL Er AL SAWMILL CARRIAGE DOG Filed Mayv 14, 192e 2 Sheevts-Shee't 2 WL m 4 l m :NLM m m W Patented Aug. 26, 1930 UNITED STATES WILLIAM C. BIDWELL AND ARTHUR M. KIRKWOOD, OF PORTLAND, OREGON SAWMILL CARRIAGE DOG Application inea May 14,

Thus the ideal mode in which such holdingv can be effected is to pull the log against the knees along an inclined plane which bisects the angles formed by the vertical rfaces of the kneeswith the horizontal faces of the head block; and we purposed to accomplish such result.

- yIn short, by our invention we effect saidy `result by providing a log dog element andr power operated means for moving the same whereby to draw the log into and firmly hold the same in the angle formed by the faces of the knees with the faces of the head'block.

In other words in one embodiment of our invention the dog ing element is supported by an inclined guideway, and the force applied for moving said element is adapted to resolve itself into vertical and horizontal 0 components, with the result that the dog is drawn firmly into the said angle thereby assuring that the log will be rmly held both against the knees Aand down on the head block.l

A further object is to provide a convenient means for adjusting the log upon the carriage and securing it in the proper position for taper sawing.

A further object is to provide a means for discharging the piece remaining upon the carriage after the final cut has been made.

' These and other incidental objects of our invention, the details of construction, and mode of operation are hereinafter described 1928. Serial N'o. 277,399.

in detail with reference to the accompanying drawings.

In the drawings:

Fig. l shows an end view of a saw mill carriageequipped with our dogs and illustrates'them in engagement in a log.

Fig. 2 shows a top plan view of one of thefknees of the carriage and illustrates the relative arrangement of our dogs.

Figure 3 shows diagrammatically the relative positions of the principal moving parts of the dogs when engaged in logs of different diameters.

Figure 4 shows diagrammatically the relative adjustments of two sets of dogs with respectto the carriage and knees thereon, when the log is secured in position for taper sawing.

Figure 5 shows a fragmentary portion of the framework upon which is a graduated scale which indicates the positions of the dogs.

Figure 6 shows diagrammatically the manner of discharging a piece from the carriage by an action of the dogs peculiar to `7Q our invention.

The reference numeral l indicates a carriage of usual construction upon which several head-blocks such as 2, and transversely adjustable knees such as 3, are mounted. The dogs of our invention adapted to the various stations upon the carriage are of similar construction.

VA frame l is rigidly attached to the knee 3 as by bolts "5 and 6 extending through the knee. An integral part of this frame 4 is an oblique way arranged at an angle somewhat less than 45 degrees with the horizontal, consisting in two symmetrically formed parallel members of T cross section as 8.

Slidable in this way is a cross-head 9 symmetrically formed with reference to a central plane parallel with the plane of projection of Figure l. This cross-head 9 is formed in detail so as to provide a pair of racks l0 and 11 with which two pinions, fixed upon the saine shaft as 12, and driven by the reversible motor 14 through appropriate gearing, engage to provide for reciprocal movement of the cross-head in its way. A further feature of the cross-head 9 is an inferior projection 15 affording two seats for the springs 16 and 17, and a place of attachment for the arms 19 and Q10 through the medium of the equalizing bar 21.

The equalizing bar 21 pivotally atached at its middle to the cross-head 9 and is held in an approximately vertical position when idle by the springs 16 and 17. The attachments of the arms 19 and 2O to the equalizing bar 21 are also pivotal.. The arms 19 and 2O are armed with spikes 22 and 23 to engage the log.

A chain 25 is secured at both its ends to the upper arm. 19 as shown at 2G and 27. Within the biglit of the chain loop thus formed are two sheaves 29 and 29 mounted. upon the upper and lower arms respectively, and an actuating sprocket 39 engaging the chain and in turn driven by a second sible motor through appropriate ig,

It will be understood that when sawing narrow timbers it is essential to safety to maintain a certain clearance between the dog spikes and the saw line, and that the lower dog may not be in riew of the operator. In consequence of these circumstances, the setting of both dogs must be gagedk from the top of the timber, and this in turn makes it`imperative that both dog spikes be maintained, in accurate relationship to each other' with respect to extension toward the saw line. Hence, in order to adapt any form of pivotally mounted pairs of dog arms to practical use, account must be taken of the varying horizontal extensions of the dogarms occasioned b y the disposition thereof at different angles, with respect to the horizontal, when gripping logs or cents of different dimensions.

In the device of our invention, both dogarms-may be maintained at equal angles to the horizontal by adjustment of the crosshead 9 in its way. The cross-head way is disposed at such an angle j ireferably less than 45 degrees with the horizontal as to provide for the required lowering or raising of the pivoted ends of the dog-arms so that they may be situatet at an equal height with the center of the log or piece being cut, and at the same time account taken of the varying extensions of the dog-arms beyond the knees as measured horizontally, occasioned by the varying angles included between the dogarms when used for logs or pieces of different dimensions. This compensation is represented in Figure 3.

Although only two controls are employed, this device has three distinct functions of great practical utility; they are, namely,

that of grippingr the log, of providing for the fair engagement of the dogs by a vertical adjustment of the pivoted ends of the dogarms that insures security for a very wide range of dimensions of the work, and of drawing cants or timbers fairly against the knees or setting out an end thereof for taper sawing.

The means for the accomplishment of both the functions of angular adjustment of the dog-arms and the adjustment of the timber' upon the carriage are identical. These two functions are not simultaneous but sequential in practical operation.

After a final cut has been made, the sprocket 30 is Vcaused to rotate in a clockwise direction. The ascending part of the chain 25, being secured to the upper dogarm 19, lifts that arm and its spike out of engagement, whilst the lower dog-arm, containing the sheave 29 in the biglit of the chain is allowed to drop out of engagement with the timber by virtue of the release of the tension on the descending part of the chain. The length of the chain 25 is such as to provide for the support of the lower dog-ar1nv slightly below the face of the headblock 2 upon which the timber rests. The cross-head 9 is then caused to recede slightly and the sprocket 30 operated in a counter clockwise direction until the upper dog-arm 19 is slightly below the top edge of the timber. The cross-head is then actuated to extend the dog-a 1ms until the timber has been cast off the carriage. This is illustrated by Figure 6.

As the carriage returns to the loading station, the knees are drawn back carrying the dogs with them, and at the same time the cross-head 9 is moved forward a nd upward, and the dog-arms are separated widely by a clockwise rotation of the sprocket 30. The dogs are now ready to receive the next log.

lVhen the new log is charged upon the carriage it may not fairly a .st the knees by reason of the violence with which the log is cast upon the carriage, or by reason of the disposition of its center of gravity, or irregularity of figure. The sprocket 30 is now set in counter clockwise rotation and the spike 23 will descend into contact with the log following which the lower spike Q2 will rise into contact on the under surface of the log; ultimately the spikes will engage the log securely.

The cross-head 9 is now drawn back ard and the log is brought into hrm contact with the knees. If now it is desired to make a taper cut, the cross-head of the dog serving the small end of the timber is adjusted to move the log into the desired alignment as indi ated by a pointer 9n carried by the crossl head 9 and registering on a scale el on the. frame 4 as shown in Figure 5, where it may be held rigidly by the combined efforts of the two or more dogs with which the carriage is equipped, as shown in Figure '-l.

rhe squared cant, owing to the eccentricity of the annular rings in the timber and other natural causes, will usually become distorted immediately after the initial cuts are made. 'lhis distortion may be winding or twisting, or bowing or bellying, or both. If further cuts are made at this juncture, the resulting timbers, or boards are very liable to be of irregular thickness. It is the primal purpose of this device to constrain the cant to its original gure by the action of the several cross-heads and dogs, to the endy that lumber may be cut of uniform thickness and more nearly exact dimension; an important economy in saw mill, and correlated operations.

It will be observed that a cant in the grip of the doos will not be moved toward the knees in exactly parallel motion owing to the constant change of the angles between each of the dog-arms and the cross-head way occasioned by the dissimilarity of the directions o travel of the log upon the head block, and the cross-head in its way. It is the function oi the equalizing bar 21 and the two springs 16 and 17 to allow of a Compensating adjustment of this aberration eifected by the forcible constraint of the cant against the true surfaces of. the knees.

Having described our invention what we claim is: Y

l. In saw mill carriage dogs, a frame adapted to being rigidly attached to the carriage knees and lformed with a way inclined to the horizontal in a vertical plane, a slidable cross-head adapted to said way, a pair of dog-arms pivotally mounted upon said cross-head, a motor and gear to actuate said cross-head reciprocally in said way, and a motor and gear to open and close said dog-arms.

2. In saw mill carriage dogs, the Combination of a frame adapted to being rigidly attached to the carriage knees and provided with an oblique way the angular relationship of which to the horizontal is less than forty-five degrees, a slidable cross-head operative reciprocally in said way, a pair of dog-arms pivotally mounted upon said cross-head, inotors'and gears to actuate said cross-head and said pair oi dog-arms respectively.

3. In saw mill carriage dogs, the combination of a frame adapted to being rigidly attached to the carriage knees and provided with any oblique way the angular relationship of which to the horizontal is less than `forty-tive degrees, a slidable cross-head operative reciprocally in said way and actuated by a motor and gear, a pair of dogarms pivotally mounted upon said crosshead, a motor and gear for driving a sprocket superposed with respect to said pair of dog-arms, a chain the ends of which are secured to the upper one of the said pair of dog-arms engaging with said sprocket, and a sheave attached to the lower one oi the said pair of dog-arms disposed within the bight of said chain.

fi. ln saw mill carriage dogs, the combination of a frame adapted to being rigidly attached to the carriage knees and provided with an oblique way the angular relationship of which to the horizontal is less than forty-live degrees, a slidable cross-head operative reciprocally in said way and actuated by a reversible motor and gear, a pair of dog-arms pivotally mounted upon said cross-head, a motor and gear for driving a sprocket superposed with respect to said pair or dog-arms, a chain the ends of which are secured tothe upper one of the said pair of dog-arms, at a point niedially of the length of that arm, engaging with said sprocket, sheave attached to the lower one ci the said pair of dog-arms, a second sheave attached to either ot the said pair of Vdogarms near the pivotal end thereof, or to the said cross-head, and both of which said sheaves and said sprocket are included within the bight of said chain.

5. In saw mill carriage dogs, the combination or" a frame adapted to being rigidly attached to the carriage knees and provided with an oblique way, the angular relationship of which to the horizontal is less than forty-live degrees; a slidable cross-head operative reciprocally in said way and actuated by a reversible motor and gear; an equalizing bar mounted upon said crosshead and retained in a vvertical position when idle by two opposing springs; a pair of dog-arms pivotally attached to opposite ends of said equalizing bar; a motor and gear for driving a sprocket superposed with respect to said pair of dog-arms; a chain, the ends of which are secured to the upper one of the said pair or dog-arms ata point medially of the length of that arm, engaging with said sprocket; a sheave attached to the lower one or" said pair of dog-arms, a second sheave attached to either of the said pair of dog-arms near the pivotal end thereof, or to the said cross-head, and both of which said sheaves and said sprocket are included within the bight of said chain.

6. In a saw mill carriage, the combination with the carriage knees, of a frame supporting a way inclined to the horizontal in a vertical plane, a cross-head movable on said wai dogs pivoted in said cross-head, means adapted to move said cross-head on said way, and means adapted to operate said dogs in any operated position of said crosshead.

7. In a saw mill carriage, the combination with the knees, of a guide way inclined to the horizontal in a vertical plane, a dog carrying element movable on said Way, means adapted to operate the dogs in any position of said element, and means to move said element whereby the 10g hed by the dogs is drawn into and rmly held in the angle formed by the faces of the knees with the faces of the head-block.

VILLIAM C. BIDVELL.

ARTHUR M. KIRKVVOOD. 

